It’s unlikely that he would have shared the manifesto and also unlikely that he shared his beliefs in any details with others, beyond possibly his brother David.

Remember that Kaczynski largely lived as a hermit from 1971 until his apprehension in 1996. He had very few connections to other people and hadn’t even spoken to his brother since 1985. The FBI found him after they published his manifesto broadly in major papers hoping someone would recognize the themes or writing/formatting style. Kaczynski’s style was very unique and the FBI had already narrowed down his educational background, age and areas where he grew up and likely had lived from it.

David was the only one who called the FBI IDing his brother as a Unabomber suspect. I’m not sure to what extent David recognized his brother’s ideology vs writing style in the manifesto, but I know that he provided the FBI with writing samples that convinced them that Ted was the Unabomber. I do know David has been interviewed and has written extensively about what happened and his decision to go the FBI, so I’m sure you could dig up whether Ted had shared his ideology with David pretty easily.